I was once told that in the early development of the human foetus - we are neither male or female, and therefore before the sex is determined embryos have nipples. Also a foetus is predominantly female.
that's true. It's also the reason women have a clitor*s, it's left of nerve endings from the penis. I'm not sure about an embryo being predominantly female but the rest is true.
As already suggested, until about the 14th week of human gestation, when the various hormones kick into action, the foetus is not gender-related. However, by that time, the tissue that will become nipples has already started forming. As a result, men as well as women have nipples.